Check JSON value instead of error_code

Checking (result.error_code != JSON_NO_ERROR) is equivalent to checking
result.value (which has a base::Optional type, convertible to bool).

The error_code enum is really a private implementation detail. Callers
don't care about it (other than it being an error or no error). Removing
references (outside of //base/json) to that enum will let us more easily
modify the //base/json implementation.

Bug: 1070409
Change-Id: Ifffa60fa05d5dd2f52fabe0a2d6794db187e0f1a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2147400Reviewed-by: sebsg <sebsg@chromium.org>
Reviewed-by: Vincent Boisselle <vincb@google.com>
Commit-Queue: Nigel Tao <nigeltao@chromium.org>
Cr-Commit-Position: refs/heads/master@{#759057}

chrome/browser/autofill/automated_tests/cache_replayer.cc

@@ -428,18 +428,12 @@ ServerCacheReplayer::Status PopulateCacheFromJSONFile(
     JSONReader::ValueWithError value_with_error =
         JSONReader().ReadAndReturnValueWithError(
             decompressed_json_text, JSONParserOptions::JSON_PARSE_RFC);
-    if (value_with_error.error_code !=
-        JSONReader::JsonParseError::JSON_NO_ERROR) {
+    if (!value_with_error.value) {
       return ServerCacheReplayer::Status{
           ServerCacheReplayer::StatusCode::kBadRead,
           base::StrCat({"Could not load cache from json file ",
                         "because: ", value_with_error.error_message})};
     }
-    if (value_with_error.value == base::nullopt) {
-      return ServerCacheReplayer::Status{
-          ServerCacheReplayer::StatusCode::kBadRead,
-          "JSON Reader could not give any node object from json file"};
-    }
     root_node = std::move(value_with_error.value.value());
   }
 

chrome/browser/autofill/captured_sites_test_utils.cc

@@ -111,17 +111,12 @@ std::vector<CapturedSiteParams> GetCapturedSites(
     JSONReader::ValueWithError value_with_error =
         JSONReader().ReadAndReturnValueWithError(
             json_text, JSONParserOptions::JSON_PARSE_RFC);
-    if (value_with_error.error_code !=
-        JSONReader::JsonParseError::JSON_NO_ERROR) {
+    if (!value_with_error.value) {
       LOG(WARNING) << "Could not load test config from json file: "
                    << "`testcases.json` because: "
                    << value_with_error.error_message;
       return sites;
     }
-    if (!value_with_error.value) {
-      LOG(WARNING) << "JSON Reader could not any object from `testcases.json`";
-      return sites;
-    }
     root_node = std::move(value_with_error.value.value());
   }
   base::Value* list_node = root_node.FindListKey("tests");